The present invention relates to a method for installing a wiring harness in an aircraft and to a tool for implementing said method.
An aircraft comprises many electric wires used in particular for transmitting electrical energy or information, commands or signals between various electrical elements of the aircraft.
For the remainder of the description, an electrical element is understood as an element connected to one or more electric wires, using the electrical energy transmitted by an electric wire and/or supplying electrical energy to an electric wire and/or able to receive and/or transmit information, a command or a signal carried by said electric wire. For example, an electrical element can be an actuator, a sensor, an electronic card, a calculator, a source of electrical energy, an electrical receiver or the like.
A wiring harness comprises a collection of electric wires which are gathered and connected to one another by connectors and/or clamping collars. Each electric wire of a harness comprises, at each end, a connection means for connecting it to another wire or to an electrical element. Each electric wire can have a specific connection means or one and the same connection means can be shared by several wires.
The electric wires of a harness can be of different lengths. Thus, several electric wires can form a subassembly forming one branch of the harness.
A wiring harness follows a specific path in the aircraft, depending on the electrical elements connected and on the path options left available by the other elements present in the aircraft.
According to one mode of installation, in an electrical and electronics (E&E) bay of an aircraft, some harnesses are fastened to crosspieces which support the floor separating the E&E bay from the cockpit or the cabin of the aircraft.
A first limitation is that, as a wiring harness has no intrinsic rigidity, it must be connected to the structure of the aircraft at regular intervals by means of fasteners such that it follows its path.
A second limitation is that a wiring harness can be tens of metres long. It is therefore bulky and can represent a large mass to be lifted up, of the order of one hundred kilograms.
According to one mode of operation, integrating a wiring harness involves unrolling the harness and then placing it in the correct position with respect to the path which it is to take. The harness must then be fastened at regular intervals to the structure of the aircraft and/or to the elements present in the aircraft; it must then be connected to the various electrical elements.
A third limitation is that these various operations must be performed most meticulously as a wiring harness is fragile and must never be bent during these various operations.
Given these limitations, integrating a wiring harness into an aircraft can require ten or so operators.
These various operators must be able to correctly manoeuvre the wiring harness even in areas which are crowded with numerous already-installed elements or items of equipment, as can be the case in an E&E bay.
The presence of numerous wiring harnesses in certain areas such as the E&E bay therefore makes it necessary to impose an additional limitation at the stage of designing and installing the various items of equipment of said areas. Thus, this limitation generally makes it necessary to leave relatively large accessible spaces so as to allow the harnesses to be installed.
However, this limitation goes against an important principle of aircraft design, specifically that of reducing the space taken up by technical elements so as to increase that available for areas of high profitability such as the passenger cabin or the baggage hold.
An aspect of the present invention proposes a method by which the installation of a wiring harness in an aircraft, even in a tight space, can be simplified.